Agreed... though I'll be curious to see what ends up happening with notifications on Linux. Firefox 3.6 still hasn't merged the patch Ubuntu uses to send its notifications via libnotify and I'm not sure about Firefox 4.

Perhaps more interesting, when they implemented the notifications for web apps, Google specifically justified implementing their own notification system with "OS-native mechanisms like libnotify aren't powerful enough." ...which I can understand as a developer (especially given Ubuntu's efforts to design a more crippled notification daemon), but I'm not sure I can excuse as an end user.